SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc61390e02e5716b8b733440a97cc5b7164a43f35a4b7e30e3479cfc50e46581' 
  AND token = 'cV1EKIH3By9+JpgmGgOYdFjCDTCpHuVRwyNo0O8CPDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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