SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '06b2cfd646daab288953e0e6bf76a7ef0044a06df1bc420e67b54c7e0a519f4e' 
  AND token = 'qVQR/LkgoKIHrV2ItaCkViJ7TR+V8sAxHxpYppZavmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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