MySQL Count(Table1.ColId) Where IN (any of Table2.Col1 ,Table2.Col2)
Look for

SELECT COUNT(t1.Id) FROM Table1 As t1     
{ INNER | LEFT } JOIN Table2 AS t2 ON t1.Id IN (t2.T2Column_1,
                                                t2.T2Column_2,
                                                t2.T2Column_3,
                                                t2.T2Column_4,
                                                t2.T2Column_5);