SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '325362ca516af5503d84ca210176cdb6f43c9cec8ed3957e1f98edcfe672f8e2' 
  AND token = 'q0q/Jq7gRnf1mVBHOa6LGOf1C7WHJl1AvzsW33WxqLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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