Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e50a53bbea164b5a155f471d3d0511d02ca3122c89d06104c030073d33caa40a' 
  AND token = '31mLfk4F197NIOA6lVKYzdkBE1hyeYBElUp6zE5sv1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

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