SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cba070d33d44ea6df4fe7421fb1d10cf0ca797a5c36ec9bcbd13ff584158d711' 
  AND token = 'LwGh6KLBtIeG/VAb9njIt8CLJvwYcrxfbZxFC+1pRT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00087

JSON explain

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