SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ba54989da4405d456c912108516f8b4690daf1150a7b3db1e7eaf7812807701' 
  AND token = 'kz1DVTq8c9BWAEYYP4lkxWDgZbhXKCeQKIlQ5IqUvz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}