SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baebfd94b9d7416e3741863473d80977a2a08bcb8cb958b7926b455cebb18f7b' 
  AND token = '2PPROUMmR0KCBiQOK73nqeUeMR0rofjOyWp4ZNuqc34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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