SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff7a244bd598e70f353cd4ee03075dfc6562721db8f412692cccb3cbf313ecb4' 
  AND token = 'DQGi0Ss+Q94O40nV3m9czfBNa8DEt/JV/4bA0OWvaSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00109

JSON explain

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