how to allow the key to only open 1 door rather than all of them?

I've been working on this script and I was wondering if anyone knew how to allow the key to only open 1 door rather than all of them as I am making a puzzle game.

Key Script: public class DoorKey: MonoBehaviour {

 public bool inTrigger;

 void OnTriggerEnter(Collider other)
 {
     inTrigger = true;
 }

 void OnTriggerExit(Collider other)
 {
     inTrigger = false;
 }

 void Update()
 {
     if (inTrigger)
     {
         if (Input.GetKeyDown(KeyCode.E))
         {
             DoorScript.doorKey = true;
             Destroy(this.gameObject);
         }
     }
 }

 void OnGUI()
 {
     if (inTrigger)
     {
         GUI.Box(new Rect(0, 60, 200, 25), "Press E to take key");
     }
 }

}

Door Script:

public class DoorScript : MonoBehaviour {

 public static bool doorKey;
 public bool open;
 public bool close;
 public bool inTrigger;

 void OnTriggerEnter(Collider other)
 {
     inTrigger = true;
 }

 void OnTriggerExit(Collider other)
 {
     inTrigger = false;
 }

 void Update()
 {
     if (inTrigger)
     {
         if (close)
         {
             if (doorKey)
             {
                 if (Input.GetKeyDown(KeyCode.E))
                 {
                     open = true;
                     close = false;
                 }
             }
         }
         else
         {
             if (Input.GetKeyDown(KeyCode.E))
             {
                 close = true;
                 open = false;
             }
         }
     }

     if (open)
     {
         var newRot = Quaternion.RotateTowards(transform.rotation, Quaternion.Euler(0.0f, -90.0f, 0.0f), Time.deltaTime * 200);
         transform.rotation = newRot;
     }
     else
     {
         var newRot = Quaternion.RotateTowards(transform.rotation, Quaternion.Euler(0.0f, 0.0f, 0.0f), Time.deltaTime * 200);
         transform.rotation = newRot;
     }
 }

 void OnGUI()
 {
     if (inTrigger)
     {
         if (open)
         {
             GUI.Box(new Rect(0, 0, 200, 25), "Press E to close");
         }
         else
         {
             if (doorKey)
             {
                 GUI.Box(new Rect(0, 0, 200, 25), "Press E to open");
             }
             else
             {
                 GUI.Box(new Rect(0, 0, 200, 25), "Need a key!");
             }
         }
     }
 }

}