SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5ac1f5ad7776c1afeb5d66639eba1f99ebfdb978357ea96d7008a6bad6f8b14' 
  AND token = 'fdMtX+SzXqB6SQ7U+UboiFpl00TcEtV8SzzgkgIBZoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}