Are you sure this warning is spurious? Basically it means that %SQL::Wrapper::q is not used anywhere else, at all, for example this code doesn't produce the warning:

{
        package SQL_Wrapper;
        use strict;
        use warnings;
        our %q;
}
package main;
use strict;
use warnings;
my %q = %SQL_Wrapper::q;
$q{f} = 42;
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but this code does:

{
        package SQL_Wrapper;
        use strict;
        use warnings;
#       our %q;
}
package main;
use strict;
use warnings;
my %q = %SQL_Wrapper::q;
$q{f} = 42;
[download]

What is setting/changing %SQL_Wrapper::q in your program or modules that your program is using?