SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c4a70a208b5aa2e0d15f5658a53f9e03c684142d2cf5b3a4353a858fa3ef73a' 
  AND token = 'YTbyXR64AKDrBZFoRmqvaR9ca+C93SuNF5O8VbAXqJs=' 
  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