SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5baede9d759b791dd4c45cca15eb671834004e528e0924a739d55cbfef3e52f9' 
  AND token = 'YziSe/TFkAJyJpDQbrLGZk1NSwX9TKv0hm/jCvfhqcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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