(Reuters) – The U.S. Federal Trade Commission is investigating whether Visa Inc and Mastercard Inc’s security tokens restrict debit card routing competition on online payments, the Wall Street Journal reported on Monday, citing people familiar with the matter. The credit card giants are already being probed by the Commission for allegedly blocking merchants from routing payments over other debit card networks, the report said. The FTC has expanded its focus in recent months to examine whether the companies’ security technology, which replaces sensitive account information with a unique digital…