I am looking for a car rental but my flight does not get in until 1:30 am. Is there a car rental that stays open that late? Or are they all closed?

Most rental car facilities will remain open 45 minutes after the last commercial flight arrives. Even if the rental car company you chose is closed; the ones remaining open will take your reservation, provided they have cars available and possibly at the same rate you booked with the original.

I recommend trying Turo. Many hosts operate 24/7 and you can pickup & return anytime.