SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bfcd9138577c0f3c43d444fdf8813015fba568e9460091cd879caf61f0be178' 
  AND token = 'Fx9ucVC7zMEjWQSZm3EA7I44NohoheJLng3Zf0ksdp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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