SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8012badcddeecb2db160faaff207bd98fe96638d58a3dda793a1be1c399a6c94' 
  AND token = 'yH78qRGEo0shpcoJUzZYrf6tQM+dTJ1t1ZHzbchIPDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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