SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9c17810df95465a38aca6ac9660e98cb5c73859bf29ef5d63c74e225dfe5485' 
  AND token = 'WmACJeFi6VzyTHzTUaZfaKpOs2fxlwUidtLWNjsCmaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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