Answer-Yes, you definitely can follow the keto diet while eating paleo. The two can actually go together really well.
The main requirement of the ketogenic diet is that you restrict your carbohydrate consumption to a low-enough level to induce ketosis. That usually means no more than 5% of your daily calories should come from carbs. Beyond that, the traditional keto diet recommends that you get about 75% of your calories from fats and then the remaining 20% from protein.
Where you get your fats, protein and carbs from doesn’t really matter on the keto diet (from the perspective of getting your body into ketosis). The important thing is to restrict carbs down to induce ketosis.
So, as a paleo eater, you could easily obtain all the fats and proteins you need for keto, from your preferred food sources. And, since most paleo followers don’t consume processed carbohydrates, restricting that macronutrient should be easy.
The only potential area of conflict would be with eating fruit. Most fruit is relatively high in carbohydrates, so a paleo dieter that is used to eating a lot of fruit and then transitions to a keto diet, will need to manage those carbs within their daily limits.