SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ca4c0e5d0bc210e4722dd9193add85b7ec7f09dba60fb6973aa7580b2e5a820' 
  AND token = 'BDZg2AtK2cyvzSlYwNgRWnCBlEkWQ2H7Btk0JZtMAe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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