Edit in JSFiddle

.align-center-flexbox
{
    display : -webkit-flex;
    display : -moz-flex;        
    display : -ms-flex;            
    display : flex;                
    
    -webkit-flex-direction: row;
       -moz-flex-direction: row;
        -ms-flex-direction: row;    
            flex-direction: row;        
    
    -webkit-align-items : center;
       -moz-align-items : center;    
        -ms-align-items : center;    
            align-items : center;        
}
 
.box 
{
    width : 200px;
    height: 200px;
}
 
.box1
{
    background-color : #61b7cf;
    height : 150px !important;
    
}
 
.box2
{
    background-color : #b964d4;
}
 
.box3
{
    background-color : #f3fd72;
}

<div class="align-center-flexbox">
    Some text
    <div class="box box1">box 1</div>
    <div class="box box2 align-center">box 2</div>
    <div class="box box3">box 3</div>    
</div>