SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7568d57871a02837750369eac55c6eb08c300b870f6f0730d180b3a3e9bce5b7' 
  AND token = 'YqBPCikFuHgqEOzdiZe5D6aL5dVEz9wtCdYuVsmOv1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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