SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd19e054092541c50fa70cd2baacc607f4a638745c75ff55fc90d29a35c42655f' 
  AND token = 'zWUutMVsxOdXuJsiQV9dcUMaAdrCF4z7YKa2/F5B4dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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