SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '168d3110dbefdc2bfc325af773ebb0a0bafd40c87844fa9287e264b65ae8527c' 
  AND token = 'Bd36hYBTdJZLxmHFFleNB3cTTNEgmFrpKlZocglXz8M=' 
  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"
    }
  }
}