SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f48e6cd5b50f7f061ab81935fd5db612fabfd746ee142938918edca4952d2f3' 
  AND token = '1zc28iMWBlNh/3EORVGgWfMtG7Y70JJg7HjB4WRHPCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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