SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7483aaed786e498360890d1dd15ebc5d380c0d63ceb66a8651eee770839f58c' 
  AND token = '1ogWbZ9U8TG/W7txTdXgZxEYmuLMxykiR86SgbJ3Dic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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