SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce683dafe3f82d17d141920fa9e353ec96c036e2cefd272b112cc00ce236acf' 
  AND token = 'WNo/7sVQjCEy503CtcjUsUnbRvdsSvLEvvY2wG7weN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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