SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8943387e506c4b4f85e6293b049b2ed4d58f37abe3b5eac5a1e8195bc6156d8f' 
  AND token = '3HQJC3vyuSq0mQ2O/m8vpgffxbIIKkHYuKTpQoI+wIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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