SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9aaf85203ef0084309ab1f0ef43cfb033141bffe18140a76e0396d1bd59ada33' 
  AND token = 'Z/NES7eRPQZSj2FiklE9Bhu9qSETA3f3hQXVpjpWsxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}