That's a hell of a lot of Ks but the state of the engine is dependent on a lot of factors such as the type of driving it has done (city vs highway), the model (and therefore the engine type), how well it's been maintained, any repairs or replacement parts, etc., etc.
You can't tell what condition the timing belt is in without looking at it unless it's making noise which would indicate that it is badly worn. It gets replaced at one of the major services (every 120,000kms I think) so, if it's been serviced regularly, it should have been replaced fairly recently. Check the service history.
I suggest that you get it looked at by a mechanic and also check the service book (if you have it). The mechanic should be able to tell you what sort of condition the engine is in, including the timing belt. If it's been well looked after and the driving history is favourable (eg. if it belonged to a sales rep or someone who typically did long highway trips and easy driving), there's every possibility that it has another 100,000kms left in it at least but without more details, it's very hard to tell for sure.
Hope this helps.
TV