SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c6f432b6d7f3bfbc5c8721aecb1b9ff66bd6f460727cb61805d516c88ad08a' 
  AND token = 'oCYkgwbfpsCeWg4vClQtj5jAkpkpbK/PSIO1XBEdaUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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