SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f73b67b06477c558b5eadff5e7b508b25d8a04cc8360750da06f89e0de537a9' 
  AND token = '3Wuabwxn6G5it/J5srPuREV9GBvjP5ajaxKlQorby3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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