SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2618a342ea387db1f29bea45da60cb13b7bb901101ad41af0f2b0f1c60fd136' 
  AND token = '19vjInS+cEQu2gsKYy6m8HZrVtqLzJKPSBX/93jFJzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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