1990 Nissan Maxima timing belt

I recently bought a used 1990 Nissan Maxima with 109,000 miles. The car has been very well maintained as far as the body, interior and overall appearance. It looks like a new car in every aspect but, I have a concern about the timing belt, as it is recommended to be replaced every 60,000 miles. It would have had to have been replaced at this point. I have no service records and can not track down the car's history. I removed the timing belt cover and inspected the belt. Of the 25% of the belt I could see, there is not any missing teeth and there are not any cracks in the sides of the belt, also when I twisted the belt, it would only twist about a quarter turn, meening it has the proper tention. I don't know what I should do as if the belt breaks, I am looking at major motor damage. I would appreciate an honest answer as far as, is the car driveable and if this is something that needs immediate attention. Too many different answers from too many people.