SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da8c69001939d9337460871780791cb0ba9fa7b41d9f0c6905249ef5c87e941f' 
  AND token = 'vn+1PSFEnxVE8bw4ZocdeASJ+F0lxdDYhC/xYC5cMfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}