https://graph.facebook.com/debug_token?input_token=USER_ACCESS_TOKEN&access_token=APP_ACCESS_TOKEN
Reference: http://stackoverflow.com/questions/10149065/find-expire-time-for-an-access-token
https://graph.facebook.com/debug_token?input_token=USER_ACCESS_TOKEN&access_token=APP_ACCESS_TOKEN
Reference: http://stackoverflow.com/questions/10149065/find-expire-time-for-an-access-token