SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id 
FROM 
  cscart_products as products 
  INNER JOIN cscart_product_features_values as c_var ON c_var.product_id = products.product_id 
  AND c_var.lang_code = 'fr' 
  AND c_var.variant_id = 3 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'fr' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'fr' 
WHERE 
  1 
  AND companies.status IN ('A') 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.parent_product_id = 0 
GROUP BY 
  products.product_id 
ORDER BY 
  product asc, 
  products.product_id ASC 
LIMIT 
  0, 20

Query time 0.00559

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "if(NULL is not null,NULL,descr1.product), products.product_id",
      "temporary_table": {
        "table": {
          "table_name": "companies",
          "access_type": "system",
          "possible_keys": ["PRIMARY"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "shared_descr",
          "access_type": "system",
          "possible_keys": ["PRIMARY", "product_id", "company_id"],
          "rows": 0,
          "filtered": 0,
          "const_row_not_found": true
        },
        "table": {
          "table_name": "cscart_categories",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "rows": 9,
          "filtered": 100,
          "attached_condition": "(cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H') and cscart_categories.storefront_id in (0,1)"
        },
        "table": {
          "table_name": "products_categories",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["chevnudb1.cscart_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "using_index": true
        },
        "table": {
          "table_name": "products",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "status", "idx_parent_product_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["chevnudb1.products_categories.product_id"],
          "rows": 1,
          "filtered": 96.4912262,
          "attached_condition": "products.parent_product_id = 0 and products.company_id = 1 and (products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A'"
        },
        "table": {
          "table_name": "descr1",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "product_id"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "ref": ["chevnudb1.products_categories.product_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(descr1.lang_code = 'fr')"
        },
        "table": {
          "table_name": "prices",
          "access_type": "ref",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["chevnudb1.products_categories.product_id"],
          "rows": 1,
          "filtered": 83.42116547,
          "attached_condition": "prices.lower_limit = 1 and prices.usergroup_id in (0,0,1)",
          "using_index": true
        },
        "table": {
          "table_name": "c_var",
          "access_type": "ref",
          "possible_keys": [
            "variant_id",
            "lang_code",
            "product_id",
            "idx_product_feature_variant_id"
          ],
          "key": "idx_product_feature_variant_id",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["chevnudb1.products_categories.product_id"],
          "rows": 2,
          "filtered": 16.59751129,
          "attached_condition": "c_var.variant_id = 3 and c_var.lang_code = 'fr'",
          "using_index": true
        }
      }
    }
  }
}

Result

product_id product company_name product_type parent_product_id
28 Cordelette corde et cuir F.R.A. Cinty Cheval Pied Nu P 0
74 Cordelette cuir cheval Kripton F.R.A. Cheval Pied Nu P 0
112 Enrênement pour la longe taille COB - FRA Peli Cheval Pied Nu P 0
111 Enrênement pour la longe taille full - FRA Peli Cheval Pied Nu P 0
61 Fourreau de Muserolle en mouton NATURE 28 cm - FRA Cheval Pied Nu P 0
60 Fourreau de Muserolle en mouton NOIR 28 cm - FRA Cheval Pied Nu P 0
72 Lame de remplacement FINE pour rape de parage jaune - FRA Cheval Pied Nu P 0
73 Lame de remplacement GROSSE, pour rape de parage rouge - FRA Cheval Pied Nu P 0
24 Licol de travail - F.R.A. lazy - PONEY beige Cheval Pied Nu P 0
44 Licol de travail en nubuck et nylon 6 mm F.R.A. capal - COB rouge Cheval Pied Nu P 0
27 Licol de travail en nubuck et nylon 6 mm F.R.A. capal - PONEY noir Cheval Pied Nu P 0
50 Licol de travail F.R.A. JABAR - CHEVAL Rouge Cheval Pied Nu P 0
51 Licol de travail F.R.A. JABAR - COB Rouge Cheval Pied Nu P 0
42 Licol de travail F.R.A. lazy - CHEVAL Navy Cheval Pied Nu P 0
43 Licol de travail F.R.A. lazy - COB Navy Cheval Pied Nu P 0
41 Licol de travail F.R.A. lazy - PONEY Navy Cheval Pied Nu P 0
88 Longe de travail ronde, 4,20 mètres - FRA Cheval Pied Nu P 0
46 Longe en coton 8,5 mètres - FRA pardi Cheval Pied Nu P 0
79 Pierre de l'Himalaya 2,75 kg Cheval Pied Nu P 0
58 Pinceau à sabots marron Cheval Pied Nu P 0