SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66f4eb0eefc3670f3500037bb01869f52d3f4ed5f43ff4de277454323dff468b' 
  AND token = 'HqZUFmUAN6BkPjJUI9BlZuNNQSJTPDJXVxdjNndee3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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