CSS Flexbox align 1 item horizontally and 2 vertically

I have the following HTML:

<div class="icon-box"><div class="icon"><svg>...</svg></div><h3>Title here</h3><p>Lorem ipsum dolor...</p></div>

My CSS:

.icon-box {  display: flex;}

The result:

How can i get the following using flexbox without changing the HTML:

I am trying to align the icon to left and the heading and paragraph to its right on the same column. Without changing/adding new HTML.