SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daed86eae7cca9264cac92e1d5836d49974d66c94b4844b922871915012ed957' 
  AND token = 'gnwmLiEbEXxWcWlMZ5lDlnekWtUiO7hMEJrP5u1F/5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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