SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '22a98c7c686523885283a15d1e6f0babbc3087c750909286f1cc3bdbcbc1e43b' 
  AND token = 'hMl7kwyKGkWC3GdADz8bzefHniZra5sZn0RD/ajpgfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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