Preheat broiler. With kitchen shears or large, sharp knife, cut lobster tails down back on curved side of shell. Pry sides of shells apart to expose meat. Top meat with garlic and butter. Squeeze lemon juice over lobster meat and dust liberally with Cajun spice and seafood seasoning. Set lobster tails in roasting pan and broil 4 to 6 inches from heat for 12 to 15 minutes, until meat is opaque in center.