SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '74d63676b9d457d032a8ff87a3eb73e5b8cb659691a6c869ceca432b65626551' 
  AND token = '8eZ0dCpqqHAIwxUG5OFwbYONUKRIp74uQJEU1cWvTIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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