SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f6adad29d473e5a4311c8137ab6e68606cbc4a7d61160dbdc89e5a7c71e2c39' 
  AND token = 'GsRUd48Sa8tzxm3xvxRjxRT5hpHiDc3VK+jjuUXTHPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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