Cant store number generated from str_random() into MySQL

i cant store the number generated from str_random() function. database stores all other inputs but not this, its always empty. it doesnt even show an error. it just stores it as empty text. i even checked with dd() function the $token variable contains a random string even after storing it to the database. its strange, i need help!!

public function store(Request $request)
{
    $token="";
        $chatToken1 = str_random(16);
        $chatToken2 = str_random(16);
        $token = $chatToken1.$chatToken2;
     ChatMessage::create([
         'to_user_id'  => $request->get('to_user_id'),
         'from_user_id'  => auth()->user()->id,
         'message'  => $request->get('chat_message'),
         'chat_key' => $token,
         'status'   => '1'
     ]);