SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a99a304cecb02c5b76bfb96162d2f7264ae0d8234ea5164f6fd782dd04d1b087' 
  AND token = 'jSStj0xJIOy3uVPJ8+B0XtLbicML7D0MCWTvQdIpgNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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