SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '499dd51e949082de3179146b8a318f2ed8bc157b985e47390d23dbc7dd8a76f4' 
  AND token = 'RPzP5hkWwgVwvGe/3hQE2hl6zIUNPgfeNvxWDZmSd8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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