SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0fed082a4d7569632b99d62c88280f1432ae95e10bd6b2844ffa0cad499983eb' 
  AND token = 'YxDKYr5+Ws9Gn8IZlRER/q+Nu6Q+utUyxJWVJ9b0XOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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