SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '360a0e190e6c8d26443363f94e9be41d48ed9297e49a8ecedef0cba672f4c5f9' 
  AND token = 'r97FPqqKPhziVJVoO/qLAPDO1bPnfwtQoPYuESUaF7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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