SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '175cf86b0473ec233876784f2c1eda8cf8a658cfe176738127d30db42d2e1d88' 
  AND token = 'jUaqe2XaGDPhw5JkKrst+aKuGYIRhjASzHyIzFJzIf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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