SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59de30262a621e3357e0c6bff577386ef79ae599920c63fbfe01d3854cbd8d46' 
  AND token = 'VJXbchg00BqPK2JAb4yDYueRtjtFPjPQNl+7pGs8+1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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