This seems like a tricky question to answer as both boxers have a very different fighting style and belong to different eras. It's easy to say that Tyson Fury would have the reach advantage due to his height being just under 7 feet, but if I had to pick one I would pick Mike Tyson due to the sheer ferocity of his boxing skills.
Mike Tyson would probably seek to cause a lot of body damage with his signature hooks to the liver and use Fury's long gait to sneak inwards for body shots. It would be interesting to see how Fury is able to limit the body damage caused by Mike by using his world-renowned reflexes.
I must still say that it would be a very close fight as both of them are greats of the boxing world!