SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '354e6882654fafc5a24c537a3ea7f6f5ad6ad2e0ab4c64aec28ef9d067826ac8' 
  AND token = 'Z2ijxTb+1AGcn6pBuVc8xaP2qhKL8phtppVS4od7DCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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