JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box" data-id="1">Primeiro texto</div>
<div class="box" data-id="2">Segundo texto <a class="link">Clique aqui</a>

</div>
<div class="box" data-id="3">
<a class="link">Clique aqui</a>

</div>
<div class="box" data-id="4">Testando</div>

JavaScript

function temSoClasse(elInicial, seletor) {
    return $(elInicial).filter(function () {
        return this.querySelector(seletor) && $(this.childNodes).filter(function (i, el) {
            return el.textContent.trim().length;
        }).length == 1;
    });
}
temSoClasse('.box', 'a.link').css('color', 'blue');