Preheat oven broiler. Grease broiling pan or line with aluminum foil. Mix Parmesan cheese, butter, mayonnaise, and lemon juice together in a small bowl. Season with basil, pepper, onion powder, and celery salt. Mix well and set aside. Arrange fillets in a single layer on prepared pan. Broil on one of top racks of oven for 3 minutes. Flip fillets over and broil for 2 more minutes. Remove fillets from oven and cover with Parmesan mixture on top side. Broil until fish flakes easily with fork, about 3-4 minutes.