use Bio::SeqIO;

my $in = new Bio::SeqIO(-file   => 'filename',
                        -format => 'fasta');
my %seqs;
my @idlist = qw(456-3210 4670-5490);
while( my $seq = $in->next_seq ) {
  my $id = $seq->display_id;
  $id =~ s/gb\|//;
  $seqs{$id} = $seq;
}

my @seqlist = grep { defined } map { $seqs{$_} } @idlist;