SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd5377ddeb6ee2896a7331247112ab4ac62a0178be1218370ab0d91dc7c3e2d' 
  AND token = 'gzT9HKcOXMwCXOCfmEM7Mq1IqGPxuTdOVU5NWT3RJ0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}