SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12c79162c0a06bfec22736a8e27bf24c0c8002ae2f932d4457d493616664f2fa' 
  AND token = 'Hdozne2TTMz/PqwvqabMuvzUzLd619+OVDc+Nx4wklk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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