SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da4879581e63225513a948af417057e6c18581c67e0107b5d6bb2db6567ca53b' 
  AND token = 'IBIcPvcWPtpDTDlDQEiI3U8PQ+jLrqR6xoqq5d6BZTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00084

JSON explain

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