SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fbc36b9e9984f008368ff3b9f9304a96ec4294090a0a610e0ee23ac9bd047e9' 
  AND token = 'UiUy472Q3Lh2naeKjRKNFspMImJxRzAUsdGIH0TReWo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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