My 163CC Kymco does not specify a mileage for belt replacement - but it does ask that the CVT be inspected at your mileage.
So, yeah, at your mileage, it would be a good idea to open up your CVT and clean things up, (belt dust?), measure the belt for wear, look at the roller weights for flat spots, lightly groom the clutch pads and inside the bell, etc.
Me, if it isn't too expensive - and while you've done the work to open the belt cover - I'd replace the belt and rollers with new Kymco parts - for many more miles of worry-free, like-new riding with your new parts!! IMHO- few things make a scoot feel-ride more like new than new CVT parts!
Stig