Changing scenes in the main menu takes a long time, what should I do?

Question

Unity

Changing scenes, for example from the main menu to the settings scene, takes a very long time, about 1-1.5 seconds, which is a very long time for a mobile phone game. What can be done?
Profiler shows that Loading.UpdatePreloading is 14.4 kb and takes 93.65 ms
. I guess I wrote the scene change script badly. I created a GameObject and attached the following Script:
public void OpenSettings() {
Application.LoadLevel("Settings");
}
public void OpenShop() {
Application.LoadLevel("Shop");
}
public void Close() {
Application.LoadLevel("MainMenu");
And I attached this GameObject with the script to the Button in the On click menu.
Maybe this method is primitive, help me understand what's wrong.