Place flour into a shallow dish. Beat together buttermilk and eggs in a second shallow dish. Mix together bread crumbs, cornmeal, garlic powder, and paprika in a third dish.
Dredge tomato slices in flour, shaking off excess. Dip in egg mixture, then press both sides into cornmeal mixture.
Preheat the air fryer to 400 degrees F (200 degrees C). Brush the fryer basket with olive oil.
Working in batches, place breaded tomatoes in the prepared fryer basket, ensuring they do not touch each other. Brush the tops of tomatoes with olive oil.
Cook in the preheated air fryer for 12 minutes, flip tomatoes, and brush again with olive oil. Continue cooking until crisp and golden brown, 3 to 5 minutes more. Remove tomatoes to a paper towel-lined rack to keep crisp. Repeat with remaining tomatoes.