1. Cook quinoa: In a saucepan, bring water to a boil. Add quinoa, reduce heat to low, cover, and simmer for 15 minutes. Remove from heat and let it sit for 5 minutes, then fluff with a fork.
2. Cook shrimp: In a skillet, heat olive oil over medium heat. Add shrimp and cook until pink and opaque, about 2-3 minutes per side.
3. Combine ingredients: In a large mixing bowl, combine cooked quinoa, shrimp, cherry tomatoes, cucumber, red onion, and feta cheese.
4. Dress salad: Drizzle lemon juice over the salad, season with salt and black pepper, and toss to combine.
5. Serve: Serve immediately or chill in the refrigerator for 30 minutes before serving.