How to correctly mark unlocked posts by the user?

I have created a custom post type with categories. Users can unlock access to individual posts with the collected points.

I would like to display in the user’s profile (BuddyPress) a list of all posts grouped by category and with the indication of whether the user has unlocked the post.

I have no problem with displaying the list of posts in a given category, it looks like this:

$xyz_args = array(
    'post_type' => 'books',
    'tax_query' => array(
        array (
            'taxonomy' => 'books_cat',
            'field' => 'slug',
            'terms' => 'xyz',
        )
    ),
);
$xyz_query = new WP_Query( $xyz_args );

if ( $xyz_query->have_posts() ) {
echo 'Posts in category XYZ:';
while ( $xyz_query->have_posts() ) {
    $xyz_query->the_post();
    echo '<a href="' . get_permalink() . '" title="'. get_the_title() . '""><img src="' . get_the_post_thumbnail_url() .'"></a>';
}
}

To display all posts unlocked by the user, I use a special mycred function. This is what it looks like:

$user_id = bp_displayed_user_id( );
$purchases = mycred_get_users_purchased_content( $user_id, $number, $order, $ctype );

if ( ! empty( $purchases ) ) {
    foreach ( $purchases as $entry ) {
        if (has_term('xyz', 'books_cat', $entry->ref_id)) { // display if the entry is in a specific category
            echo '<a href="' . mycred_get_permalink( $entry->ref_id ) . '" title="'. mycred_get_the_title( $entry->ref_id ) .'">';
            echo '<img src="' . get_the_post_thumbnail_url($entry->ref_id) .'">';
            echo '</a>';
        }
    }
}

I would like it to look something like this in the user’s profile:

<h4>Posts in category XYZ</h4>
<a href="..." class="locked" title="Unlock now">...</a>
<a href="..." class="unlocked" title="Post X">...</a>
<a href="..." class="unlocked" title="Post Y">...</a>
<a href="..." class="unlocked" title="Post Z">...</a>

<h4>Posts in category ABC</h4>
<a href="..." class="unlocked" title="Post A">...</a>
<a href="..." class="locked" title="Unlock now">...</a>
<a href="..." class="locked" title="Unlock now">...</a>
<a href="..." class="locked" title="Unlock now">...</a>

I don’t know exactly how to put it together. Can anybody help?