SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fa8efb535d67107fadf61f5d8514d9e5ee9f2f781fdf2c818dc09b9ae8907ae' 
  AND token = 'ug6OQiq65kFmhqHFigkWzwqfrsS1QToiIvJ9dMvT0yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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