In a large skillet, heat the butter, then add the garlic and crushed red pepper and cook until fragrant, about 1 minute.
Add shrimp to the pan and season with salt and pepper and paprika; cook until shrimp turns pink, 2-4 minutes, depending on their size, and remove with a slotted spoon.
Add the vegetable broth, red wine vinegar and lemon juice to the sauce leftover in the pan, scraping the sides, and cook until sauce thickens slightly.
Turn off heat, then toss the spiralized zucchini with the shrimp to warm slightly. Serve with Parmesan cheese and fresh parsley, if desired.