SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f1557b67c7d32dd2e1a83350d40d6c4c32594b41914898cfa7f6a34d329666' 
  AND token = 'qFSulkwBmjrrVyWJUvh5z16YxefVoSqmZfSgdhluOgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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