SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea355ac9b1621e71311dc81bcd6ff645bcfdad36a63669f43228ca6e32468391' 
  AND token = 'zmp9Pn/ecwWSFvEZ5YnAxh1NeKDO4uHc5HXYUiWGBAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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