SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40c60c170a4dfb656f6ba590dc8cfa40cd17112492ecca002f7a2b258419f63d' 
  AND token = 'QDGXmCSKg1dZYWEV/t+qRdHmI7gvQ5MjB2+v84RQdqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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