SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e7d6c52b6a228388c9ed2922b7ad7d24a144c9a800e738db673a1f64522fccd' 
  AND token = 'vBYBVFVK0MLB71Qgp/DWtamc2/qiGy4aVBrUH/ZDIGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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