SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac501ffc702413fd3dbfb75ccc0b882b8ae19fec19003092642b1d665b61170' 
  AND token = 'vp8jyuVMFERsPM18tHZDEF+ZSI6Pd/T2l9+uXWxneL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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