SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47fc998fda15b20c2b914e32a79b31eb3d9df89dc225155b80b66b50332ee076' 
  AND token = 'os3AkpEo/T5sAJNEnhGhPfzgJ2QYtnYLJfZ+AYL+VIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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