SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e52f42581c8020c9fd826d75073f4c5164f9a0ec5c0f958c132da9a5a295af0' 
  AND token = 'J6C4dMVpQjbf6LXquvbXQv52yG7uFO9OqkRMMNxYdq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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