SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1685d6a6def6c9e7406932ed415d0faba4b98bf958b049d863d8e9ac7811fab' 
  AND token = '1KlhWoxxj5xrFHVoLxMMdtfS3fDEm5dnbuXMnAWEhhg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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