检查对象是否具有php / laravel中的值

I almost finished my website, just one more feature to finish and this is so the user can like just once a post/theme/discussion point(whatever).

I have the table new_theme_user:

    1 id 
    2 id_user(integer) 
    3 id_theme(integer)
    4 upVote(tinyint)

So this is the controller:

class Vote extends Controller {

    public function VoteTheme($id, $vote){

        $Vote = DB::table('New_Theme_User')->where([
        ['id_theme', '=', $id],
        ['id_user', '=', Auth::id()],
        ])->get();  (1!!!)

        if (!isset($vote)) {   (2!!!)

        if ($vote === 'plus') 

        DB::table('New_Theme_User')->insert([
        ['id_theme' => $id, 'id_user' => Auth::id(),  'upVote' => 1],
        ]);

        else 

        DB::table('New_Theme_User')->insert([
        ['id_theme' => $id, 'id_user' => Auth::id(),  'upVote' => 0],
        ]);

        if ($vote === 'plus') {
            DB::table('New_Themes')
            ->where('id', $id)
            ->increment('upVotes', 1);
        } else {
            DB::table('New_Themes')
            ->where('id', $id)
            ->increment('downVotes', 1);
        }
        }

        $Themes = NewTheme::paginate(5);

        return redirect()->route('welcome', ['Themes'=>$Themes]);

    }
};  

1!!! - Is the select query which creates an object(in order to find in database if someone has already voted before the theme/post which he wants to vote again.

2!!! - Is the if statement, if the object doesn't have the values - this means the user can vote once so it populates the DB with information.

The problem: I can't figure how to work around the (2!!!), I tried isset, empty, whatever else I could find on internet, it doesn't work, even if the user voted once more the if goes through and it seems I can't find a solution. Every given help, I will greatly appreciate. Thank you!

NewThemeUser model

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class NewThemeUser extends Model
{
    protected $table = 'new_theme_user';
}

Now in controller you can do like this

App\NewThemeUser::firstOrCreate(['id_theme' => $id, 'id_user' => Auth::id()])->increment($upVotes ? 'upVotes' : 'downVotes');//This will fetch the first record if there any exists for the user then increment if $upVotes then the column to increment is upVotes else upVotes