SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f7a8795540ab268843b6687671956fb0b87e3895abc4af37ee4aa27e0874085d' 
  AND token = 'Denhv3Lok07ZIQV/u5Um/UPQZ9ATJr7y/Wo9dFRjBV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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