SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96467a7a6e75477ac49ecd7e0a7811d24071343aa392c81b2e59ccc8973c9140' 
  AND token = 'deJ8rSLvefSic8VtVjByaogTDTVwF50N/NzeRLfguUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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