SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26872155c6bbf27aff33eec9cff7f1cf0de3fb8774c024faf48bfb46be470bff' 
  AND token = 'sRxCFFDlq3L9ZdFtRAn7ZdfRmOZFUB+Rvr8n9VQBxMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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