SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1199eb506c6311fc9a8e35183a7c0bee0173ffcdd30b8bcd44ebc434e04e7bf' 
  AND token = 'WsAmNgYnLXmk5j14ZSwNC5S1biLalV5kkAJq9XcRe0o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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