SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '845cb8262c32ab5205ad6b42869e28bf0dcfbc145d00c268922d84a37ac1c191' 
  AND token = 'px7ithFxIzpYVg4xQVH4cu4Ndvvwvp3SnIZpcHRYGFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}