How to validate the checkbox is selected or not using Selenium Webdriver?

Selected Checkbox Webelement details:-

<label class="container_checkbox">
   <input type="checkbox" class="Control Checkbox" value="on" style="display: inline-block;">
   **<span class="checkmark">
     ::after
   </span>**
</label>

Not-Selected Checkbox Webelement details:-

<label class="container_checkbox">
   <input type="checkbox" class="Control Checkbox" value="on" style="display: inline-block;">
   **<span class="checkmark"></span>**
</label>

To indicate the checkbox is selected the developer is using CSS ::after selector. How can I check whether the checkbox is selected or not using selenium webdriver.