SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c29c18f2467ad63f471a9cb84b43a997767f9277c3ef24dfa51987424d170e9' 
  AND token = '+LZzZ3hRv+djjsYSDScVb47XlKk+TdBHJErM+B9QsNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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