Preheat oven to 375 degrees F (190 degrees C). Place crab legs in a shallow baking pan.

Heat butter in a small saucepan over medium heat until melted, about 3 minutes. Whisk in seafood seasoning, lemon juice, garlic, and olive oil. Brush crab legs with butter mixture and pour any remaining mixture over crab legs.

Bake in the preheated oven until opaque and flaky, basting regularly with the butter mixture in the pan, 25 to 35 minutes.