SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6ccc7749a0bae7d005fdc5060086e854367984c9200345a703a84e2966f9d69' 
  AND token = '6Imr+961KtjLbzZOi+zDPNOug3tWHnYocv1e7473Z8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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