SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64e63f03293cca83577a041aca36375af0adaed9a35c4b098b740587c897e048' 
  AND token = 'X0/CgP4prekGgpvMqqE5CdXifU5pepELbZElJ38Lw7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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