SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '243bf16fecc27064131a37d545397599d43c516e18ce56775845a9e502375996' 
  AND token = 'ZTjq8+WXwpHEJlO2PK3ZD8OhiHxDzO6batym7ZpCg6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

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