Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbe7fccd7801515e5a44ce64d1f2f96bf31f7862bfcaa14c1fc90cc9afa1d3c6' 
  AND token = 'KpDjnxvIGJDaxbpL9Zt7plw4CqxU9V51WT9VWTRS2d4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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