SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5564f7a907dd784baac17d779d473c8d138ca83d54b66f53a627c1a2b415d6c1' 
  AND token = 'GaDdDNch8TNh3659neMqqx4jqoYrYY89D9NUO1ReIqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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