SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5700902f3939d06cdc67bf847b414eab99a481b0c1b5bef771f56ca275616e8a' 
  AND token = '2uuEgOOA+HvGk/xAEmF/wHkWwj5Pp4c0nVK2+zfIyyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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