SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3af481e88dd8f8910528f7ce366ee18becff73dd6ccbd838adb9e3ef550598fe' 
  AND token = '2ZeC05vzMW0dWm0/6GclkdpKCErD18FfojiuwQ/YJVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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