Remove cache on an individual block in Drupal

This can be done by overriding the individual block settings, by updating its cache age to 0.

Target an individual block in the preprocess hook in the .theme file.

function theme_preprocess_block(&$variables) {  
 if (isset($variables['plugin_id'])) {
    if ($variables['plugin_id'] == 'system_branding_block') {
      $variables['#cache']['max-age'] = 0;
    }
  }
}