SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '481980802af03cdba797890160e5057825faa3887678bb43495b107e95eb1ad5' 
  AND token = 'xUlpa5mwlyTo3YHCNchKf1ztvNnnK91bMI0/6OpbGXU=' 
  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"
    }
  }
}