Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b44e0116b1b2814c3ef9feaf0e5d946e15b6bc254e842ea1eb3474465281dc5' 
  AND token = 'ZCNOxs1nGgEGuNiEF5vQSu8FB7xhBKC5CLpdlIgdUZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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