SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '986529843eb05b1e777c0cb0caae8d4f17b5e2916f03162b5bbf8b2d075da589' 
  AND token = '44njzmrOruKyXWePBJsky0K0R1fqAji63mry29BuIU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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