I have a flight at 5:35 AM from Košice (KSC). Unfortunately I'm 2.5 hours away by train, and the first train in the morning doesn't get in until 4:10. I don't think this is sufficient time to get a taxi to the airport (first bus doesn't leave until 4:40), check in, check my bag, and get to my gate.
So my other option is to go the night before. The last train arrives around 11pm. If I get a taxi to the airport, can I stay in the pre-security area overnight? Does the terminal building actually close at some point? Will I get hassled by security/the police and asked to leave?
The last flight out is between midnight and 1 AM. The last flight in is around the same time. The first flight in is at 4 AM, so there's no regularly scheduled air traffic between 1 and 4 AM. I couldn't find anything about hours of operation save for one random person's comment that the pre-security area is public space open 24/7 -- but I'd like confirmation before attempting.