SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac3ac5654ac880e3bf687eeea4861ad71d03ad404ac605b4039baa7855254b36' 
  AND token = 'SbRi/Wjv58sXOQFJvCaNwye/Zv84CvOKRIaKJM9SR/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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