In a medium bowl, toss the shrimp with ¼ tsp salt and the ground pepper.
Heat 2 teaspoons of the olive oil in a large nonstick skillet set over medium-high heat. Add the shrimp and cook until the shrimp are just cooked through, about 1 minute per side. Transfer the shrimp to a plate.
Add the remaining 1 teaspoon olive oil to the skillet and add the shallots. Cook, stirring, until the shallots are soft, about 2 minutes. Stir in the red pepper flakes.
Add the snap peas and cook until the snap peas are just tender, about 3 minutes.
Remove the skillet from the heat and stir the shrimp (and accumulated juices), pistachios, lemon zest, basil and the remaining salt into the snap peas. Serve immediately.