Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6390ebadb332d004706adeded539e078f245b18cb834671ee9fe5d9f61361c7b' 
  AND token = 'F5QAwWDP3k/Q3Umo2TtTun2st1TRpr8VeOTYQgCvKBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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