I'd recommend not going to the hotel for such a short period even with boarding pass. There is plenty of construction going on around the airport and you never know how the traffic will be.

If you land at 3:00, (You didn't say international or domestic, baggage or no baggage etc) it could take an hour to get out.

You will barely get an hour of sleep, between check-in and check out.

Let us know what you ultimately did.