SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c88e0302a49fb3613b3567430108f884eb743307d31fbdc6bc71715c27bd09a' 
  AND token = '0XGdJJE1ON7CvxcIPJNlCdvm3gocvNm8xleAkntCgwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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