Paper accepted three hours after submission
It's impossible that the paper was reviewed (at least by a human). 3 hours is way too short. Weeks is a much better order of magnitude estimate for the time required to review papers. 

It sounds like you're dealing with a predatory conference. I would approach with care. Check if the conference's scientific committee are actually established researchers in the field, check the keynote speakers to see if other established researchers are intending to attend, check if the conference has been held before and if so, how those conferences went.