SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52f83f03e8b5415f0fd5622ed48e061d267386433c060dcb1e22f887e06a7587' 
  AND token = 'IdCQatos9YODi/ADR4g1m73lf3wWlFwQ9bG0dXohcOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}