SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '88316a378ced5c7b727279420772b55ec00d9104127a66f2512ae69eb88cbc54' 
  AND token = '3eFjsLohx9RTC/A1HCzVWiFoDysqxfKRF+xiZ980sZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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