Hi anat0l,

This sounds like a real problem. Prague is a small airport but even with carry-on you wouldn't be able to make it in time as long as you don't consider a cab. My guess would be, you're at the Hilton around 08:00 pm -08:15 pm. From here you can walk to the venue (~30 min), take the metro or tram and walk a few more minutes (~ 15 min.). I'll send you a PM with further information, asap.