Yes, there is a Purchase Status API to get the status of the in-app billing from Google via http.
Google Play provides an HTTP-based Purchase Status API that lets you remotely query the status of a specific in-app product or subscription, or cancel an active subscription. The API is designed to be used from your backend servers as a way of securely managing in-app products and subscriptions, as well as extending and integrating them with other services.
You can get an overview on the Android Developer Site and a reference on Google Developers.