SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd012f6f6a047aa6b1ca78ee7c653a45d6d59b042228a890f8ec5bc272be4974f' 
  AND token = '/GKLyzVfF+JqNmh1x8kaIYBj4PDdh8pluntnSKvd7Mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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