AirBaltic flights are cheap, but you always have a layover in Riga International Airport (RIX). Leading flight resellers offer flights with only 45 minutes layover time in RIX.
Is that even possible for EU residents?
If it's on the same ticket, it's not your problem. They have to allow enough time, or all their passengers will be running into the same problem. Odds are good that it might even be the same plane (eg Qantas from London to Sydney via Bangkok, you get off in Bangkok, walk through security, turn around and come back onto the plane, all in an hour.
If it's two separate tickets that you bought, however, then that's a different matter - it's up to you to make sure you have enough time between the flights to get from the first to the second one.
Air Baltic actually covers this on their website. It's worth noting that Riga airport is VERY small, and they consider the minimum connecting time to be 25 minutes.
That link also explains what you'll need to go through, depending where you're flying from/to.