SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '619c94dceaf1611880bb87351e44572c0d5358d298c402bac1c40cf39acedf60' 
  AND token = '1TdwJWVTXCbHO/jk4w//CqLtOMN3c3759uzUsFG1m8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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