Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6875f93c8cc34bf4238108caca58fe549dc8a7115ea143f72a6082cf83cd06f6' 
  AND token = 'r9h5u5de7WHxv0H2AIwmuDK9VqlOEnOpacJOoSmuG3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

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