SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aed642fc53f192ed979f7a0e8e69a41a9927dbeecfbc4ff4dcd6b5f41d91c73d' 
  AND token = 'viwDEXeJtFiydMihxWRmg26itKOzfYoFE+LeT4j5To0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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