SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8078cbd0f079f1560b09519392b196f854fca0c51be097248410f919d9348e65' 
  AND token = 'VO0wj4Q6nh7UZEJ/c7An7O4wB9WTKrIKmNNpHBTdl6g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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