I wouldn't worry too much. If you have a reasonably sized carry on that's overweight, they will let you through, especially if you have paid for a check-in bag.
They typically eye-ball your carry on. If it's is a wheeled carry on, they might weigh it. If it is a small'ish back pack they probably won't.
Worst case, pay for enough check-in luggage including your camera gear and carry on... Never had an issue with AirAsia, Thailand or anywhere else in SE Asia,..