I took the Airasia for Shenzhen - KL, KL - Langkawi earlier Jan this year. Shenzhen - KL was one hour delayed due to some passengers' visa issue from last flights, KL - Langkawi was completely on time. On Airasia website it shows a on-time rate for past months, sth like 85% or 90%, which I think is pretty good. It is only one hour flight from Langkawi to KL so I conservatively think it is ok for your connecting flight for the fact that it will be in the same terminal, and both domestic flights which mean no visa/passport check.
Anyway in case you really miss it, you can always buy a new ticket for the continue lag, domestic flights of Airasia are quite cheap.
Anyway in case you really miss it, you can always buy a new ticket for the continue lag, domestic flights of Airasia are quite cheap.