how do you disable a key for 5 seconds?

I want to disable the key S for just 5 seconds, so if you press the S once do an action and within those 5 seconds if you press the S again it won’t do anything
here’s my code

    float cuenta = 5.0f;
	if(Input.GetKeyDown(KeyCode.S) && _instancia == false)
	{
		cuenta -= Time.deltaTime;
		_instancia = true;
		Debug.Log(_instancia);
		if(cuenta <= 0.0f)
		{
			_instancia = false;
			cuenta = 5.0f;
			Debug.Log(_instancia);
		}
	}

use Time to keep track and put it in your if statement, something like this

float cuenta = 5.0f;
float timer = 0f;
    if(Input.GetKeyDown(KeyCode.S) && _instancia == false && Time.time > timer + 5)
    {
        cuenta -= Time.deltaTime;
        _instancia = true;
        Debug.Log(_instancia);
        if(cuenta <= 0.0f)
        {
            _instancia = false;
            cuenta = 5.0f;
            Debug.Log(_instancia);
        }

        timer = Time.time;
    }

float lastTime;
void Start(){
lastTime = Time.Time;
}

void Update(){
if(Input.GetKeyDown(KeyCode.S) && (Time.Time - lastTime > 5.0f)){
    DoSomething();
    lastTime = Time.Time;
}}

Is how I would probably do it.