SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd254888a10fbca11f3ae73412140f945474296280d647b65c9c67752ce709626' 
  AND token = '+peHOyrdlGRsZnW/SXwyqruv6ofEtjFnt5Yl6ojzwtE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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