@fks = grep not(
    $_->table_to->name eq $orig_fk->table_from->name and
    $col->eq([$orig_fk->columns_from], [$_->columns_to])
    ), @fks;

# OR

@fks = grep
    not
    $_->table_to->name eq $orig_fk->table_from->name &&
    $col->eq([$orig_fk->columns_from], [$_->columns_to]),
    @fks;