i.keyhole,
i.keyhole::after,
i.keyhole::before {
 display: block;
 box-sizing: border-box;
 border-radius: 20px;
}

i.keyhole {
 --width: 20px;
 --height: 20px;
 position: relative;
 width: 20px;
 height: 20px;
 border: 2px solid;
}

i.keyhole::after,
i.keyhole::before {
 position: absolute;
 content: '';
}

i.keyhole::before {
 left: 5px;
 top: 3px;
 width: 6px;
 height: 6px;
 border: 2px solid;
}

i.keyhole::after {
  left: 7px;
  bottom: 3px; 
  width: 2px;
  height: 5px;
  background: currentColor;
} 

label>i.keyhole:first-child {
  left: 7px;
  scale: .9;
  border: 2.1px solid;
}

i.keyhole+input {
  padding-left: 34px;
}