World Map Help

So I’m trying to do something where you press left/right to move the cursor to the next location waypoint. Here’s what I have:

using UnityEngine;
using System.Collections;

public class WorldMap : MonoBehaviour {
	public GameObject[] MapLocations;
	int MapLocationIndex;
	public GameObject MapCursor;
	// Use this for initialization
	void Start () {
		MapLocationIndex = 0;
	}
	
	// Update is called once per frame
	void Update () {
		if (MapLocationIndex >=5)
		{
			MapLocationIndex = 5;
		}
		if (MapLocationIndex <=0)
		{
			MapLocationIndex = 0;
		}
		print (MapLocationIndex);
		MapCursor.transform.position = MapLocations [MapLocationIndex].transform.position;
		if (Input.GetAxis ("Horizontal") > 0)
		{
			MapLocationIndex++;
		}
		if (Input.GetAxis ("Horizontal") < 0)
		{
			MapLocationIndex--;
		}

	}
}

While I can move between the locations by pressing left/right, what’s going on is I immediately go from Location 1 to Location 6 by having the key pressed for less than a second.
How can I fix this so it stops at each location instead of just going through it if the key is held?

GetAxis() returns true every frame while the 'Horizontal" axes button or devices is pressed. You needs something that returns true for on the single frame where the button goes down. Input.GetButtonDown() for example, or Input.GetKeyDown().

if (Input.GetKeyDown(KeyCode.RightArrow)) {
     MapLocationIndex++;
}