SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9706f986bdaa9454e94b087967198dcb5a31c6032190f3a4ca4385efa453484' 
  AND token = 'xC/xgZUYo4a17hSmFOymkyKYsadwGJS06RkTYSuw4bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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