SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd717a1eca24458a4b8fc877bd6c555e432bbe428f076c0df4f51840d9061b9b2' 
  AND token = 'KlQriDIi2QUt+2noTZez+FrQfBdg86kqwgp+CTmGDvU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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