SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ce449ac4efdcd845e579ac39c7cece8322505f2b7c0c6c86d842b7af596aad4' 
  AND token = 'uAUl7Pfk02ijdMquio6FE9sogd2dMzjuUcculnAap4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00103

JSON explain

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