Blackburn,
Just a wild guess you left a few zero's off that mileage figure?
The '04 SLE is a six cylinder and does have a timing 'belt' that is scheduled for replacement at 90,000 miles. Your dealer should be able to check the Toyota database to determine whether that maintenance was done (if done at a Toyota dealer). Unfortunately timing belts tend to look new and undamaged right up until they break so you can't go by looks.
So, your options.
1. In a perfect world every owner of every car/truck keeps meticulous maintenance records which are left in the glove compartment when the car is traded. That paperwork finds itself into the hands of the new owner (along with the owners manual). Obviously that's not the case for you. Bummer.
2. If the dealer took the car as a trade in (didn't buy it at auction) they should have the name of the previous owner. Ask them to contact that person to find out what maintenance has been done.
3. Ask the dealer to check the Toyota database to determine what maintenance has been done over the years at dealerships. The full history should be there.
4. If there's any doubt, be proactive and change the belt. Yours is an 'interference' engine. If the belt breaks the valves left open will slam into the tops of pistons and do a lot of internal engine damage.
At 100,000 miles your engine is also due for its first spark plug change (Iridium).
Visit this website:
http://www.toyotaownersonline.com/ where you'll be able to download an owners manual (sounds like you don't have one since the belt and other maintenance items are listed inside) along with a full maintenance schedule.
Cheers