SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cc0bf48e5ad9ac89e13331f0ff32754950b654e28f653d9a960a013836eb9442' 
  AND token = 'hN8A9B0OLlauD74ZLmYjBhF5WrlUuNA69+sqkpKgl18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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