SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '456f5c6769177c5d4899103c3365395ece949db47c36139f99d38ea0cb955a79' 
  AND token = 'vrr3jj9Sldd5cdznVK3jjntKqdP6f7sLTD0KoknOpts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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