SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01fe65d715afd67c720767bced19ddfaddc7325ee184314191811c335d8f3ca3' 
  AND token = 'RpHp9FtYn6EQy14/tN7bya49aGMNAziZ+O3Hi3eJhd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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