SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e48c04ccb9feef246e90db5f12a5b38fde67d9b2d693b2fb58518c0dcfb1eb4' 
  AND token = '5U8hPaS3pGP8gVYmqzRnIhhGaH/pjB7I7uLFW/Fe7ZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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