SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0338feabb4958122f3b562582fe5994ef9ef5a0e7eee8498c4add002555a9d1b' 
  AND token = '05Ee/l5jrOnuyqJfgqHPQOjxc4+BJqsZxD+DzGWRwFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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