SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1c035556a6feb8863d529727bffbc9d97ed035cf08fa86891b4dcb76e0c736b' 
  AND token = 'dYIrrTatceAabvghVsg0EJeiPEW4zM7RrCemXnSU/Po=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}