mysql> create table test (
    -> id serial,
    -> fld1 int,
    -> fld2 int,
    -> fld3 int,
    -> fld4 int
    -> );
Query OK, 0 rows affected (0.28 sec)

mysql> insert into test(fld1,fld2,fld3,fld4)
    -> select 1,1,1,1 union all
    -> select 10,1,1,1 union all
    -> select 10,10,1,1 union all
    -> select 10,10,10,1 union all
    -> select 10,10,10,10
    -> ;
Query OK, 5 rows affected (0.08 sec)
Records: 5  Duplicates: 0  Warnings: 0

mysql> select * from test;
+----+------+------+------+------+
| id | fld1 | fld2 | fld3 | fld4 |
+----+------+------+------+------+
|  1 |    1 |    1 |    1 |    1 |
|  2 |   10 |    1 |    1 |    1 |
|  3 |   10 |   10 |    1 |    1 |
|  4 |   10 |   10 |   10 |    1 |
|  5 |   10 |   10 |   10 |   10 |
+----+------+------+------+------+
5 rows in set (0.00 sec)

mysql> select * from test
    -> WHERE (fld1=10)+(fld2=10)+(fld3=10)+(fld4=10) < 3
    -> ;
+----+------+------+------+------+
| id | fld1 | fld2 | fld3 | fld4 |
+----+------+------+------+------+
|  1 |    1 |    1 |    1 |    1 |
|  2 |   10 |    1 |    1 |    1 |
|  3 |   10 |   10 |    1 |    1 |
+----+------+------+------+------+
3 rows in set (0.07 sec)

mysql>