Cook the protein in 2 batches if you don't have a large skillet. If you crowd the pan, the food will steam, not sear.
Warm a 12-inch skillet over medium-high heat. Add oil; swirl to coat. Add shrimp in a single layer. Cook, undisturbed, until lightly golden, about 90 seconds. Sprinkle with salt, crushed red pepper and garlic; turn shrimp and sauté until just cooked through, about 1 minute longer. Transfer to a platter and tent with foil to keep warm.
Add sherry to skillet; cook, stirring to release brown bits from bottom of skillet, until liquid has reduced by about half, 1 to 2 minutes. Stir in lemon juice and juices from shrimp. Remove skillet from heat; add butter and smoked paprika and stir until sauce is creamy. Spoon sauce over shrimp; sprinkle with parsley. Serve immediately, with lemon wedges, if desired.