SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e85f78a5ca10dbcf190ac0443142b0edb88223f5cd3387e900a47a6c8281bf0d' 
  AND token = 'UUU+5l95Knv7YAjFboc1xeD5O3otLowRjZQzqbzpTjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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