SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dddd9bf7652d280d5c80ba370ab2e5c878625bd23189869e8b881bdbc13bf4af' 
  AND token = '46mrCT+vztNdBHiJpzEkoEraKNkmm8BH7zJOFU8TOmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}