Heat butter and olive oil in a large skillet over medium-high heat until sizzling. Add minced garlic and red pepper flakes; cook and stir until fragrant, about 30 seconds. Add shrimp; cook and stir until shrimp is just cooked through, 3 to 4 minutes.
Stir in fresh lemon juice and zest, and parsley. Season to taste with salt and pepper. Transfer to serving bowl or platter and serve.