SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cded48e3aa8ec902d2c945a8a77825369ee360b5fcea398abf970cb914622de' 
  AND token = 'hpUaYHMUdTsY3uJBlz7HxRGjnGtf3Gvje8XpNovBGng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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