SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '616537928848f31b35892a4f3659cfc750c2016620fa505e80fe5454d1c50872' 
  AND token = 'rAKuYMhntjZZmbtVTJmWBZXp5YP/5CY5zPC8M6k9+Zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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