Ionic gets the contacts very slow

By obtaining the contacts through the cordova-plugin-contacts plugin. When I run the script to get about 300 contacts is very delayed, it lasts 8 seconds approximately, does anyone know a solution?

Ionic Info:

cli packages: (/ usr / local / lib / node_modules)

@ionic/cli-utils  : 1.19.2
ionic (Ionic CLI) : 3.20.0

global packages:

cordova (Cordova CLI) : 8.0.0 

local packages:

@ionic/app-scripts : 3.1.9
Cordova Platforms  : android 7.0.0 ios 4.5.4
Ionic Framework    : ionic-angular 3.9.2

System:

ios-deploy : 1.9.2 
Node       : v8.9.4
npm        : 6.0.0 
OS         : macOS High Sierra
Xcode      : Xcode 9.4.1 Build version 9F2000 

Environment Variables:

ANDROID_HOME : not set

Misc:

backend : pro

Function to obtain messages:

getAllContactsFromPhoneBook() {
    return new Promise((resolve => {
      this.contacts.find(['id', 'name', 'phoneNumbers'], {multiple: true, hasPhoneNumber:true})
        .then((data: any) => {
          for (let i of data) {
            if (i.name.formatted) {
              if (i.phoneNumbers) {
                let name = i.name.formatted;
                this.contactsNames.push(
                  name
                );
                let id = i.id;
                let phone = i.phoneNumbers;
                this.contactsArray.push({
                  id: id,
                  name: name,
                  phone: phone
                });
              }
            }
          }
          this.contactsOrder = this.contactsNames;
          this.groupContacts(this.contactsOrder, this.groupedContacts).then(() => {
            this.groupedAllContacts = this.groupedContacts;
          });
          resolve(true);
        }, (err) => {
          console.log(err);
          resolve(false);
        });
    }));
}