SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfcd2a8534d394e832acf13e123507a36447f6e4b9579c83d5e5114974b80a8e' 
  AND token = 'nzZrNSuBC668ZCqz7qjMNHYed9/UHhcQYA+WDfunpZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}