If I understand your issue correctly, perhaps the following will generate what you need:

use Modern::Perl;

my %data = ();
$data{b_slash_car_bit_slash_tebla_bit} = 'b/car[10]/tebla[9]';
$data{b_slash_car_bit_slash_tesla_bit} = 'b/car[10]/tesla[0] b/car[9].
+tesla[1]';
$data{b_slash_car_bit_slash_tisla_bit} = 'b/car[10]/tesla[0] b/car[9].
+tesla[1]';

my $var1 = 'b/car[*]/te.*a';    # <-- changed this to .*
$var1 =~ s/\//_slash_/g;
$var1 =~ s/\[\*\]/\_bit/g;      # <-- changed _bit_ to _bit

say /$var1/ ? 'YES' : 'NO' for keys %data;
[download]

Output:

YES
YES
NO
[download]

Each key of the hash is checked in the ternary statement for the pattern contained in $var1, resulting in printing "YES" if found, else "NO."

Hope this helps!