MT2L03 on 5.1.... how to root?

Just updated from 4.3 to 5.1 so I can get CarbonROM, and can't seem to find how to root it now. Kingo worked fine when it was on 4.3 if I'm not mistaken (I've rooted 6 devices since then, so I may be misremembering, haha). Now, it's no longer supported. KingRoot and Towelroot have also failed. I've been googling and trying to find the answer, but all I'm getting are the above methods, for 4.3. If I've completely overlooked something and am asking a dumb question here, then please forgive me. I'd appreciate at least a web link in the right direction if that's the case, or if this is a valid question then I'd love if I could get a bit of a walkthrough with this. :) Currently, I'm running the stock ROM, unlocked bootloader, stock recovery... which was needed because I had to update