Suggestions to accelerate Laravel - excel upload

This is how I do that

    public function store(Request $request)
    {
        $request->validate([
            'file' => ['required','mimes:csv']
        ]);

        $file = $request->file('file');
        $file_name =$file->getClientOriginalName();
        $filename_exist= Shipment::where('filename', $file_name)->first();

        if ($filename_exist) {
            return back()->withErrors([sprintf('file %s exists ', $file_name)]);
        }

        $sampleHeadings = [
            "quantity","type","brand","model","product","generation","status","part_number","list_id","batch",
            "serial", "mfg_serial","note","warehouse","location","cost","availability","sold_to","order_id","sale_price",
            "order_date","shipment","visibility"
        ];

        $headings = (new HeadingRowImport())->toArray($file);
        $headings =$headings[0][0];

        $missedCols =[];
        foreach ($sampleHeadings as $sampleHeading) {
            if (!in_array($sampleHeading, $headings)) {
                array_push($missedCols, $sampleHeading);
            }
        }

        if (count($missedCols) > 0) {
            return back()->withErrors(['error', sprintf('columns %s required', implode(' - ', $missedCols))]);
        }

        \DB::transaction(function () use ($file, $file_name, &$ship) {
            $ship = Shipment::create([
                'filename' => $file_name
            ]);

            $all_products = Product::all();
            $imported  = \Excel::toCollection(new ProductsImport($ship->id), $file);

            $sku_start_number = 100001;

            $imported->first()->map(function ($import) use ($ship, &$sku_start_number) {
                $import = $import->toArray();
                unset($import['id']);
                trim($import['serial']);

                $import['shipment_id'] = $ship->id;
                $import['created_at'] = now();
                $import['updated_at'] = now();

                // Generate SKU
                // if the name already exists - get the same sku
                $same_name = Product::where('product', $import['product'])->first();
                if ($same_name) {
                    $import['sku'] = $same_name->sku;
                } else {
                    $type_2letters = $import['type'] ? substr(trim($import['type']), 0, 2) : 'PR';
                    $brand_2letters = $import['brand'] ? substr(trim($import['brand']), 0, 2) : 'BR';
                    $sku_start_number += 1;
                    $sku = $type_2letters . $brand_2letters . $sku_start_number;
                    $import['sku'] = strtoupper($sku);
                }

                $duplicate = Product::where('serial', $import['serial'])->orWhere('mfg_serial', $import['mfg_serial'])->first();
                if ($duplicate) {
                    Duplicate::insert($import);
                } else {
                    Product::insert($import);
                }
            });
        });

        return redirect('/shipments/'.$ship->id)->with('success', 'success ');
    }

this is the import class

class ProductsImport implements ToModel, WithHeadingRow
{
    protected $shipment_id;

    public function __construct($shipment_id)
    {
        $this->shipment_id = $shipment_id;
    }


    /**
    * @param array $row
    *
    * @return \Illuminate\Database\Eloquent\Model|null
    */
    public function model(array $row)
    {
        // dd($row);
        return new Product([
            'quantity'=>$row['quantity'],
            'type'=>$row['type'],
            'brand'=>$row['brand'],
            'model'=>$row['model'],
            'product'=>$row['product'],
            'generation'=>$row['generation'],
            'status'=>$row['status'],
            'sku'=>$row['sku'],
            'part_number'=>$row['part_number'],
            'list_id'=>$row['list_id'],
            'batch'=>$row['batch'],
            'serial'=>$row['serial'],
            'mfg_serial'=>$row['mfg_serial'],
            'note'=>$row['note'],
            'warehouse'=>$row['warehouse'],
            'location'=>$row['location'],
            'cost'=>$row['cost'],
            'availability' =>$row['availability'],
            'sold_to' =>$row['sold_to'],
            'order_id' =>$row['order_id'],
            'sale_price'=>$row['sale_price'],
            'order_date'=>$row['order_date'],
            'shipment'=>$row['shipment'],
            'visibility'=>$row['visibility'],
            'shipment_id'=>$this->shipment_id
        ]);
    }

    public function collection(Collection $rows)
    {
        foreach ($rows as $row) {
			//
        }
    }
}

The problem is large files give ( NGINX gateway timeout ) error .. for smaller files it is slow but OK ..

ANY suggestions are highly appreciated .. every req second matters