SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11efb2ee4faa965ea0c5d75b6374b90309f5ef64ca8d4aedff9d9847caaf9d82' 
  AND token = 'tyEb6wjh/sn2WOExFuQorDicl4xgKfCjiEGVkmUUa6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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