If I switch the dsn back to our Postgres db and not the test sqlite db, it works, but it's the same SQL generated:

cat t/47-find_unused_number.t 
#!/usr/bin/env perl
use strict;
use warnings;

use Data::Dumper;
use Test::More tests => 2;

use_ok 'API::Schema';

my $dsn           = "dbi:Pg:dbname=api;host=127.0.0.1;port=5432";
my $apidb         = API::Schema->connect( $dsn, 'postgres' );
my $ddi_available = $apidb->resultset('CompleteNumberE164View')->find(
    {
        ddi     => 441224900999,
        is_used => 0
    }
);
note 'DDI found: ' . $ddi_available->ddi;
ok( $ddi_available->ddi eq '441224900999', 'Found available DDI.' );



prove -l t/47-find_unused_number.t 
t/47-find_unused_number.t .. ok   
All tests successful.
Files=1, Tests=2,  1 wallclock secs ( 0.02 usr  0.00 sys +  0.55 cusr 
+ 0.06 csys =  0.63 CPU)
Result: PASS
[download]

The original schema was generated for Postgres, but populated via our sql fixtures for sqlite. The search goes work, so must be DBIx::Class related?