SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd377a9170f87d2f45d18333578e0016fc89bfc8d4fcf0f374bf5220e5bf77230' 
  AND token = 'xWodn1cSpeMW1MdKbJTmIiQx9Wfj/eIBTZIHnFnWiBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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