The time to ask all these questions is BEFORE you buy the car. You research the values via
www.kbb.com,
www.nadaguides.com and even
www.clearbook.truecar.com. Then you read the consumer reports on the make and model of the car. Then, because it's a used car, you have it inspected by a Toyota technician...ALL BEFORE BUYING THE CAR.
How long your particular used car will last is anyones' guess. All you can do is be diligent in the maintenance and upkeep of the car. Provided there are no hidden issues in your particular used car and it was not abused during the first 42,0000 miles of it's life, the car should be solid. Stay on top of service and it should last you for miles and miles.