I agree with everyone else here. Tyson would take it in a boxing match. They are just different sports. You have to remember that striking in MMA is much different than boxing. In boxing, neither fighter has to worry about being taken down, there are no kicks whatsoever, they would be in a ring which would make the navigation different, defense is different due to the size difference between the gloves, and the clinch is entirely different.
Carwin would have to account for all of these things and completely adapt whereas Tyson would already be accustomed to this style of fighting.