SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deb68389de6e7f99950d67e56cc18d954c3452736e33b0f9ac6370f896f869e1' 
  AND token = 'gy5r9kyJPFiz2ZujKP5hmh9Eg5BJLf0T7YGyqI6tgco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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