SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1ddea822dba0436cc96a37e946dc3324219a32609ae56581f660f66e1482c7d' 
  AND token = 'nZw3EAVLJ8zx1ahBF7WZmMSAt/EzG+kJDNSrnrKbVTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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