SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7951f274c826d42ef937485d9bf0c9a1900a440bd390b5bc7b9a8abe6f45ac74' 
  AND token = 'KiufLFQg3jGiMHbblvo+iJXczlB5+DFRuRkC7PznExI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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