KL is an airport I know well, though I prefer Supang. I digress. It is a an under-utilised and efficient airport. OP will arrive at the KLIA1 Satellite terminal and the Phuket flights normally go from the main terminal so must take the connecting train which runs every few minutes and is very quick. Usually the wide bodies use the satellite and narrow bodies fly from the main terminal. Connecting to MH is easy with hand luggage only as no need to clear immigration and customs just the security check at the departure gate. I have connected in under 30 minutes before off a late arriving plane, but that was close!

If connecting on Air Asia, you have to clear immigration and customs, then best way is to get the KLIA Express to KLIA2 which runs at 20 minute intervals and takes 3 minutes.