SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63e6eeacb4fdef700ce785b49109a6fe5f48aaec4cab36c20751f12a5bf56d90' 
  AND token = 'eTvZEnPAhGjK3T+RjgvJsuZ1jk6702eodHprrZdZEOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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