SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06481519cf79afddb319eefa95cf1ce743a2522376d3a578ee9c1206957f61f6' 
  AND token = 'YyXNinXGeu1jMHe+iQylnG+xGB07P1DX+YGPJxFFbLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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