JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
  <div class="boxrow">
    <div class="box selected">esimene rida esimene tulp</div>
    <div class="box">esimene rida teine tulp</div>
  </div>
  <div class="boxrow">
    <div class="box">teine rida esimene tulp</div>
    <div class="box">teine rida teine tulp</div>
  </div>
</div>

CSS

.box {
  height: 200px;
  width:40%;
  border: 1px solid #c0c0c0;
  margin: 1px;
  float: left;
}

.selected {
  background-color: gray;
}

.boxrow {
  clear: both;
}

JavaScript

$(document).keydown(function(event) {

    var selected = $('.selected');
    var row = selected.parent('.boxrow');
    var index = row.children('.box').index(selected);
      
    switch (event.keyCode) {
      case 37: // left
        if (selected.prev('.box').length != 0)
          selected.removeClass('selected').prev('.box').addClass('selected');
        break;
      case 38: // up
        var prevRow = row.prev('.boxrow');
        if (prevRow.length != 0) {
          selected.removeClass('selected');
          prevRow.children('.box').eq(index).addClass('selected');
        }
        break;
      case 39: // right
        if (selected.next('.box').length != 0) 
          selected.removeClass('selected').next('.box').addClass('selected');
        break;
      case 40: // down
        var nextRow = row.next('.boxrow');
        if (nextRow.length != 0) {
          selected.removeClass('selected');
          nextRow.children('.box').eq(index).addClass('selected');
        }
        break;
    }

});