SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3ca765b4f4a92a303370f576dbf871745d0e94e12e9ca51da9f47533b1fd0850' 
  AND token = '1XEpDsdMGYrymq9hAkvyzd6rcEPzrRowZdJVQV6D3hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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