SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38af8657281358ccb3872c6f112238ef9560db7a73df45027532700cc681f68b' 
  AND token = 'hVtRCXybAgNhkzEPoYzCDFLzC9HULf+EY1ZfxAjP5RY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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