If you're unsure of the maintenance history of the past, don't assume anything. Just replace it now and avoid the risk. While off, you should replace the water pump and any tensioners as well, plus any other drive belts.
Say it was inspected at 60k or so miles, you bought it at 85k miles. It now has 113k miles. It is time to replace it according to the schedule. I would highly doubt the previous owner replaced it at 60k.