SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '282d2a8b05fe71146391b0bff069581fed554721135c8af2f9aa58876b9d44c4' 
  AND token = 'IuhB/B+wKVPnmSHdlI37CmFygXYQjvRjGDuKE7QgcC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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