SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3387487c9d576efb8e6aba001b3fdd51517b6be07b18916a3264e7f25a7c483' 
  AND token = 'N8oH0FXX7cVM3DydQe16MlFOdcwJMVJ0znjPcaAec8M=' 
  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"
    }
  }
}