SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33b9e797b1499dc5ebd71d5c7c1d56998e57452270a8dd48152c1da48439c1ea' 
  AND token = 'f74Qi6uwi6MFl+AIyiWEKOmMn1W53bVdckWvktmBDuU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}