+---------+---------+----------+
| TABELA2 | TABELA1 |          |
+---------+---------+----------+
| cod1    | cod1    |          |
+---------+---------+----------+
|         | cod2    | EXCLUIDO |
+---------+---------+----------+
| cod3    | cod3    |          |
+---------+---------+----------+
|         | cod4    | EXCLUIDO |
+---------+---------+----------+

$teste1 = "SELECT * FROM tabela2 as a INNER JOIN tabela1 as c ON (a.cod2=c.cod1)";
    $teste2 = mysqli_query ($db,$teste1);
    while($teste3 = mysqli_fetch_array($teste2)){
        $teste = $teste3["0"];

        $insert = "UPDATE tabela1 SET campo = 'Entregue' WHERE cod1 NOT IN ($teste)";
        mysqli_query ($db,$insert);
    }

select * from tabela1 t1  where not exists(select * from tabela2 t2 where t2.id = t1.id )

update tabela1 t1 set t1.status = "EXCLUIDO" where not exists(select * from tabela2 t2 where t2.id = t1.id )