SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25871e1e0eb7af086967cf8eda41492134a9e5cb89a902b96c29bcbe5521cee5' 
  AND token = 'bjIjQ7nk1kkbNp24mwLlqFlLCO9knGqmYn9pgdcGGdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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