SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ddf6da1ceb802a3dc39479806d26c54f9b913dc0d37aff5c52dfb17857e17cd' 
  AND token = 'nuf5g/Yz/cHyyDzJE9a6xbBc/mlR97JsFLSZVXIOq+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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