I have some trouble writing well performing query. Now I have two tables:

Cars:

```
id   brand   model_name
1    'Audi'  'A4'
2    'Audi'  'A4'
3    'Audi'  'A4'
4    'Audi'  'A6'
5    'Audi'  'A7'

```

Buyers:

```
id   cars_id  name     activly_looking
1    2        'Brad'   'no'
2    2        'Kim'    'maybe'
3    4        'Sofia'  'yes'
4    4        'Tim'    'no'
5    5        'Tina'   'yes'

```

Now I need to select the count of cars that: HAS buyers but does NOT have any buyers who are `activly_looking = 'yes'`

The query should in this example return the count of `1`, since only car with id `2` fulfill the criteria. 

BTW. this will be done as a onetime query to debug an issue, but on a quite huge table (Millions of rows).