SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e1a64c36eb07364f6b58f1171add2870b88b7308eb64fe8a9d7fc409fadef3' 
  AND token = 'DgwyAsC/SfWs+XmWWGAgG4aHloZXxWqJEdC4dwMBHYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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