Soak wooden skewers in cold water for 30 minutes if using. Preheat grill to high heat and oil the grates.
In a large bowl, mix olive oil, garlic, smoked paprika, cumin, salt, pepper, red pepper flakes, and lime zest. Add shrimp and toss to coat. Marinate for 15 minutes at room temperature.
Melt butter in a small saucepan over low heat. Add garlic and cook for 1 to 2 minutes until fragrant. Remove from heat and stir in lime juice, lime zest, cilantro, and salt. Keep warm.
Thread 4 to 5 shrimp onto each skewer, piercing through both ends so they lay flat.
Grill shrimp for 2 to 3 minutes per side, brushing with garlic lime butter during the last minute on each side, until pink and just opaque.
Transfer to a platter, drizzle with remaining butter, garnish with fresh cilantro, and serve immediately with lime wedges.