Pat salmon skin completely dry with paper towels
Season flesh side with salt, pepper, and cayenne
Heat skillet over medium-high heat and add olive oil
Place salmon skin-side down in the pan
Gently press the salmon for 30 seconds to prevent curling
Cook without moving until skin is deeply golden and crisp
Lower heat slightly and add butter, garlic, and thyme
Tilt pan and baste salmon with melted butter
Flip salmon briefly to finish cooking the flesh
Add lemon zest and juice, then remove from heat