Toss scallops, olive oil, paprika, cayenne pepper, salt, and black pepper together in a bowl until scallops are completely coated.
Heat a nonstick skillet over high heat. Cook scallops in hot skillet until browned, about 3 minutes per side. Reduce heat to medium and transfer scallops to a bowl.
Cook and stir garlic in the same skillet until fragrant, about 30 seconds. Add butter beans, lemon juice, and Italian seasoning; cook and stir until beans are slightly golden, 1 to 2 minutes. Stir cooked lentils and arugula into skillet; cook and stir until arugula begins to wilt, about 30 seconds.
Pour any accumulated scallop juices from the bowl over arugula; stir scallops into lentil mixture and cook until heated through, about 1 minute. Season with salt and black pepper.