Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450cb691f1dcbb0bd0443610710e9cf549cad7bfe06c7bc0f0c65f1b4902cbd1' 
  AND token = 'QmKUrHyOuWRB8Cxw2BO652CmYPUMtGeVanceE6IGNDs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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