SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6604de19cf5bacd925721fb623a957eb671f4e714f10a689d023d8257df6ba73' 
  AND token = 'oaeJUImv9771aO5HNJoA0YtVlN50+vbX4kf5TG4tWnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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