refactor: add composite (collection_id, deleted_at) index to nfts table

database/migrations/2024_01_29_120936_add_collection_id_deleted_at_index_to_nfts_table.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('nfts', function (Blueprint $table) {
+            $table->index(['collection_id', 'deleted_at']);
+        });
+    }
+};