SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267a13c833a230641fbdbd4305c93a4ecdae7b2aac024b0f8d2d82bee5999144' 
  AND token = '/tzU+agl+H6zb65FOBvuvGVhfQK0u/VRLX9V+7v/yLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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