SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'badff559559f083a6f045af56e13670dd343b7ebc3912f008c4609a1ecf6cc6c' 
  AND token = 'ybnBNGknMrURAJIfysytEdTdGjOGdwswqY1Y3ZJ0x9M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}