In a medium bowl, toss the shrimp with olive oil, Cajun seasoning, garlic powder, onion powder, smoked paprika, salt, and pepper until evenly coated.
Heat a large skillet over medium-high heat. Once hot, add the seasoned shrimp in a single layer. Cook for 2-3 minutes on one side until they turn pink and opaque.
Flip the shrimp and cook for an additional 2-3 minutes until fully cooked through.
Remove the skillet from heat and drizzle the lemon juice over the shrimp. Toss to combine.
Serve the Cajun shrimp over cooked rice or quinoa, garnished with sliced green onions.