Eloquent updateOrCreate hide some columns to while updating like created_at is not updating in update operations

I am using updateOrCreate function to update the record if there record is already available in table based on some condition but I do not want to update one of my column which contains some unique value.

I want to perform the same action to this column like created_at is working while creating the records value is adding to created_at column but while updating it contains the same

to prevent this issue I removed that column name form my $fillable in my model but in this case it is not adding any value to this column

protected $fillable = array
        (
            'uid',
            'channel', 
            'updated_at'
        );

$data = [
                        'uid'                 => Helper::generateUid(),
                        'channel'             => $info['channel'],
                        'created_at'          => time(),
                        'updated_at'          => time(),
                    ]; 

                    $cond = [
                        'channel' => $info['channel'],
                    ];  

                    $isAdded = Templates::updateOrCreate($cond, $data);

Expected result : I don't want to update uid column if details already there.

Actual result : if details are not there it is add value to uid column and other columns also and if details are available then also it is updating uid column.

via Chebli Mohamed