use strict;
use warnings;

my %Hash;
$Hash{44.52}{param1}{key1} = [ 101.01, 'val1' ];
$Hash{95.01}{param2}{key2} = [ 101.02, 'val2' ];

my $neededVal = 80.0;

if (    exists $Hash{$neededVal}
	and exists $Hash{$neededVal}{param1}
	and exists $Hash{$neededVal}{param1}{key1} )
{
	print "DEFINED";
}
else {
	for ( keys %Hash ) {
		print "$_\n";
	}
}