SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '643ab1e3b37dbe458977edc224feb3708e079727ddefcf9e21634aa9c8182bc7' 
  AND token = 'josHSt9acGAgY1PJ41cJDvVEfrCY6a7qjvLYbcQOGJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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