CSRF checker on memory with Typescript

csrf.ts

import crypto from "crypto";

class CSRF {
  private store: string[] = [];

  constructor() {}

  createToken() {
    const token = crypto.randomBytes(64).toString("hex");
    this.store.push(token);
    return token;
  }

  checkToken(token: string): Promise<boolean> {
    return new Promise((resolve, reject) => {
      let i = this.store.indexOf(token);
      i > -1
        ? (() => {
            delete this.store[i];
            resolve(true);
          })()
        : reject(false);
    });
  }
}