SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9685fe87bc58e56b5612d61bc3cdf70c182abc38e3fca1da70b930431557eb80' 
  AND token = 'RBZUE5/CGSo2u7GHKp4mLlTlAvn0L7aUhG+V9QKg+Vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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