if (exists $colD{$valA}) {
    ...
elsif (! exists $colD{$valA}) {
    ...
}

##</code><code>##

if (exists $colD{$valA}) {
    ...
else {
    ...
}

##</code><code>##

...
use strict;
use warnings;
use diagnostics;
...

##</code><code>##

my $valA = $sheet->{Cells}[$row][0]->{Val};
if (exists $colD{$valA}) {
...