SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04b0d379cad4c28812ecdbbfe398cdda50f71f09812536526c70095d4ed6125d' 
  AND token = '0/+MaSblJbmzKfqh6zVZgtCQnQRnuJ66Z+k5/07wD3I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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