SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f8a5d18684a920a5204a3efdaa45e7598e843ff04557e3d2741a21a9d53d943' 
  AND token = 'mDpkE0j7Q4PyGuiJHe7F6F94jktJkytiCub1AQH7Z5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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