Position a rack in the upper third of the oven and preheat to 450 degrees F. Toss the chickpeas with 1 tablespoon olive oil and 1/2 teaspoon salt in a large baking dish, then spread out in a single layer. Bake until golden, about 20 minutes.
Meanwhile, toss the shrimp with 4 tablespoons olive oil, the garlic, lemon zest, red pepper flakes and 1 teaspoon salt in a medium bowl. Marinate 10 minutes.
Remove the baking dish from the oven and scatter the shrimp over the chickpeas. Return to the oven and bake until the shrimp are pink, 5 to 8 minutes. Drizzle with the remaining 1 tablespoon olive oil and sprinkle with the parsley. Serve with lemon wedges.