<a class="btn" href="#">
  <span></span>
  <span class="txt">Кнопка</span>
  <span class="wrapper-ico">
    <span class="ico">
      <img src="https://i.postimg.cc/yxWQmQwP/i-backet.png" alt="">
    </span>
  </span>
</a>

.btn {
  display: flex;
  justify-content: center;
  align-items: center;
  width: 100%;
  max-width: 300px;
  height: 40px;
  -webkit-border-radius: 20px;
  -moz-border-radius: 20px;
  border-radius: 20px;
  background: #FFCC00;
  color: #000;
  text-decoration: none;
  font-family: arial;
  font-size: 16px;
  font-weight: bold;
  transition: all .5s ease-out;
  position: relative;
}
.btn > span {
  width: 100%;
  height: 100%;
  text-align: center;
}
.btn > span.txt {
  padding-right: 41px;
  display: flex;
  justify-content: center;
  align-items: center;
  width: auto;
  white-space: nowrap;
}
.wrapper-ico {
  position: relative;
}
.ico {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
  width: 36px;
  height: 36px;
  background: #fff;
  -webkit-border-radius: 50%;
  -moz-border-radius: 50%;
  border-radius: 50%;
  transition: all .5s ease-out;
  position: absolute;
  top: 0;
  bottom: 0;
  right: 2px;
  margin: auto;
}
.btn:hover .ico {
  right: 100%;
  background: transparent;
}





body,html {
  width: 100%;
  height: 100%;
}
body {
  display: flex;
  justify-content: center;
  align-items: center;
}