SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd7c27e7674b0c7c66774ce7fad5a986bb9e6482f1522d4450df46cb59b61582f' 
  AND token = 'K1TBVdiBpEjv/vhEnVG3vFXQQe84+GmZqzdP8Ul7dyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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