$c = $modx->newQuery('modResource');

$c->innerJoin('modTemplateVar', 'tv1', "tv1.name='icon'");
$c->innerJoin('modTemplateVarResource', 'val1', "val1.contentid=modResource.id AND val1.tmplvarid = tv1.id AND val1.value='example-icon'");

$c->innerJoin('modTemplateVar', 'tv2', "tv2.name='isCosmos'");
$c->innerJoin('modTemplateVarResource', 'val2', "val2.contentid=modResource.id AND val2.tmplvarid = tv2.id AND val2.value='IS'");