SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e7e10f09a46520a1f90072fcf3f6031a4cd89df57438646f0f9667c7082ac86' 
  AND token = '1CRvqlLeqo8gQzangvhjmiXqiqNf1BGZvczATYhmAbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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