SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b9f2dedbbb0d4fe6674124a7a097c545bc883ff58d655eefe243f806d468bf6' 
  AND token = 'pjgHwcqULdvGpaX/JBtdCEGS8588XV3V30kA9W8QXqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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