SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5d94b4b78f82e5ca0f1d7da609a5b06ee60de41c39fd3ae424f69f292dc2b61' 
  AND token = 'EO3gJ/ofOVLvDjP0BzYj9dYbkETLcgzDuxmIkbEwZuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}