unity – Would specifiying layers cause lag?

I build the game for android before adding this code and it ran all day without lag. But when I added this code and build it, within 10-20 min it would lag. Is it possible that this code is draining performance?

 public class FishClicker : MonoBehaviour {

 public LayerMask whatIsFish;

 public float clickRadius = 0.1f;

 void Update() {

     if (Input.GetMouseButtonDown(0)) {
         var mousePos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
         var hit = Physics2D.OverlapCircle(mousePos, clickRadius, whatIsFish);

         if (hit != null) {
             var fish = hit.GetComponentInParent<Fish>();

             if (fish != null) { fish.DoClickThing(); }