SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b38ea2f6d6224bd6e16413bfc77bbe947eb8c4b20b425f3d288012df4df92f2c' 
  AND token = 'tliZdQHIMStVIMYM0iAYvrcStCdQ2EqTCFaRQ/TGIbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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