Pat the chicken tenderloins dry with paper towels.
In a small bowl, combine kosher salt, black pepper, garlic powder, and smoked paprika.
Sprinkle the seasoning mixture evenly over both sides of the chicken tenderloins.
Heat the olive oil in a large skillet over medium-high heat until shimmering.
Add the chicken tenderloins to the skillet in a single layer, leaving space between each piece.
Cook the chicken without moving for 4 to 5 minutes until the underside is golden brown.
Flip the chicken tenderloins and add the unsalted butter to the skillet.
Continue cooking for another 4 to 5 minutes until the chicken is cooked through and reaches an internal temperature of 165°F (74°C).
Spoon the melted butter over the chicken while cooking to keep it moist.
Remove the skillet from heat and drizzle the fresh lemon juice over the chicken.
Let the chicken rest for 2 minutes before serving.