SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '024813e8f9300bdea7873849da50be2ba6751aa3958374a25cd88da5be89673d' 
  AND token = 'rk8e59ihNRYhI1bLpcYvPJ4gwIWeKKWDaJTheTsUEJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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