SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8334b7ad73c335b774b74672b467b726f56b47971de534e4d9a92bf165136d7b' 
  AND token = 'fw8ssYlQ5DtppD1YLIZHEwNgD8SQanfnoKp6qPJMtRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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