Even assuming he does not have the Nemetrix, I still think Khyber takes this.
Kraven has useful weaponry which should be able to work on Khyber if they manage to hit him, but given the fact that these are both incredibly skilled hunters, with Kraven being able to hunt down Spider-man and Khyber hunting a vast array of dangerous predators from across the galaxy. So given the fact that starting distance is about 4km, it does give time for either character to set up traps and hide if they wish.
But Khyber, along with his experience and how he managed to sneak into the Plumber's base and swap Ben and Albedo, has Class M lifting strength compared to Kraven's Class 1. If we look at Khyber's fight with Rath, he does grapple and even throws his opponent, showing us that he does use his strength in physical encounters. Also, Khyber is about 9 feet tall seeing as his comparable to Rath in height.
So I think it is more likely for Khyber to come out on top in melee combat which is what I think this fight will come down to. Khyber's intergalactic experience should mean he is able to avoid Kraven's traps, while Kraven's own impressive hunting experience means he shouldn't fall for Khyber's traps either. While I do think Kraven is more skilled, Khyber has sheer brute strength to his advantage which I don't think Kraven can overcome.
Even on the off-chance the fight takes place long-range, Khyber still has an advanced rifle that technically has Relativistic attack speed, but speed is equalised anyway so I don't think this should be an issue.
Khyber takes this with high difficulty.