You might want to check the replacement cycle on the timing belt. The older models required it somewheres around there.
It doesn't matter. The engine is not an "interference" type engine. The valves will not interfere with the piston even if the belt breaks. If it breaks the engine will simply stop running and your only cost will be the cost of a new belt (and maybe a tow). With other "interference" type engines, if the timing belt breaks you will suffer multi-thousand dollar damages when the pistons crash into the valves. Not so with the Corolla.