SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73395114c57d013f3410135fe2b40e61c9da6181a1141d99a50eac8aeffbb998' 
  AND token = 'c9OD/oENxksNe9jhtuvD4euqOIYgTfDHQMHdb5Gqxgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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