SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5bfc51cf99376afbadea07cbd7b412fa82c7bbba7dd49a92cc227ed684eccc5' 
  AND token = 'xMjW6j8Kz+hG0j7o/YlWNfe9Ic//R0grFKFmbcomxrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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