SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '928e85c579feb3c3faeb226b4cc5ef5fa5f51bfb6c61e2d675804dca1569fa9c' 
  AND token = '8uuEKYftGeW9gIp2FoldyFl/Q35dq+4AzYhvfNPp6gs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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