Preheat oven to 400°F. Line a large rimmed baking sheet with parchment paper or nonstick foil. In a small bowl, stir together maple syrup, mustard and garlic powder until well combined.
Place salmon, skin side down, on lined baking sheet; sprinkle lightly with salt and brush with maple syrup mixture. Bake until fish is just cooked through and flakes easily with a fork, about 20 minutes. Serve immediately