Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '751b0aa6af67c5e33c3e01d9cb4b894866025eb462b77ef2f55e8ad9fdb39bea' 
  AND token = 'Mf8Z1G31eF439wXSOdFB6HcymsHB5uPZ42ceGzfl4gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE								Impossible WHERE noticed after reading const tables