SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dd7ebfd64ae83176b8acdf37d99bcdbb7194a5d81224c4cac83b4657d07d355' 
  AND token = 'wTDgQcxlUdjHQyYmpGUvobYYDuO5m+rfuzGN+R2LgQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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