SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'af92950dbd34b3939e731a03cf580efa864bd44651d2baf3654a43994753c3cd' 
  AND token = '8bZUH8/balgcqx0kUHb3+/+rIQkkEyiS7v2+2FYOjUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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