SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebe1ed31c097f1cd44b34488dd6c64cb71de6040fc6edf41867daf3de1454d11' 
  AND token = 'kW1TagoJ6khY0o6QyM1jhuAcEBYvLpuehU71ejwfPb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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