Lomachenko is, without a doubt, one of the best boxers in the world, at any weight. That said, mma is a completely different world. The guy he fought was not on his level. To say he would dominate in mma based on his fight tonight is laughable.
A great wrestler would put him on his ass very quickly, and he wouldn't look good at all. I'm very impressed with Lomachenko, but boxing is very specialized. You can't gauge how well a boxer would do in mma based on a boxing match. It's just not possible. Anybody that tried to stand and strike with him in mma would be so fucked that it's hilarious to think about, but I doubt anybody is that stupid.
Lol at "they wouldn't get close enough to take him down". Yes they would. A high level wrestler would just need to grab ahold of him and it's game over.