SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f0300c759583a6694d8b514d65fdf627db245afe4c9002a041d69b8e30150d9f' 
  AND token = 'kbdZ31M5BAb992okXWqCV1QNopOXzBbD1uDn70ngTAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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