I haven't flown from MMX But as it's all *A I'm sure you'll get checked in all the way.

Definitely doable at ARN especially with TK Elite status.

Your flight from Malmo should arrive at T4. It's then a 10 minute walk to T5, past all the checkin counters to the far end for security then immigration. Show your Gold card to use the express security (to the left of the main queue just past the check in counters).

After security you walk through the duty free shop then turn right if you're just on time for immigration and the non-Schengen gates or turn left if you have time to visit the lounge.

I often catch the CA flight and there can be long but moving queues at immigration for non-EU passports, but the EU queue is normally non-existent. Security is almost always quick and efficient.

So provided your incoming flight is on time you'll have plenty of time.

I do notice for this flight at least, the terminal indicators go to FINAL CALL before boarding actually starts, so if you're through immigration and see this sign don't panic. Once you're through immigration it's just a few minutes to walk to the CA gate.