Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b17a88a90b1f1394cb3eb28e1a75615e9458295155d517ddf0d2ac5efa98e88' 
  AND token = 'MY1lqjpo3myDRBRKkel4qkXpY6owqQ9VyD/aBDYrb5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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