Preheat oven to 250°F (120°C).
Mix dry ingredients: In a large bowl, combine Chex cereals, pretzels, and peanuts. Set aside.
Make the sauce: Melt butter in a small saucepan. Stir in Worcestershire sauce, seasoned salt, garlic powder, onion powder, smoked paprika, and cayenne.
Combine: Pour sauce over the dry mix and toss gently to coat evenly.
Bake: Spread mixture on a large baking sheet. Bake for 45 minutes, stirring every 15 minutes.
Cool and store: Let cool completely. Store in an airtight container for up to 3 weeks.