SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37535e96f7570d2edc369bcddca7194ea011dbf391d39298fc03c35fedbb02f9' 
  AND token = 'IgYd1Hu1o5tCAW5Y2ylSL6STrKraet3jGgtMg7m6Db8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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