SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '492ffbf94668b5b719b35b04e8ac20677839e9a9d09fea6b6fd90fe8777f20f8' 
  AND token = '5nCCJ4JcZSHgrj63y7KqPqSqZwOKWyoRjndjBkIhcUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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