SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36596751858be09fbeb5b9163967a0287e2f69871e2e831d42f0065ddc9718d8' 
  AND token = 'NJ8bJkuIhx593huw4oL0NYGoFqkLknEU7Atk1sWzTJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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