SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5f8af0d59663224af9f023eae8523f09947a6aca8d66fb850b51bf71cd58068' 
  AND token = 'KWlQSx+gwgQMPrO5QjzljQTilHfsSUX9OSPqmJU58qI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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