SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e9f01e78da55b8b56b4e2da007ac545b17f5fe74fecb7e265d42b8ffd78e1d3' 
  AND token = 'stdmogXHF5Ifzc6hBabsgWGaqQrTjIOvaW2ARAn8t18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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