SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ab0a29d79538e5d17dea1b802f5af25b1ff9a9a3676018590142157f58a8490' 
  AND token = '9ON5s+Ww3X7Q9d128vwCw7VKannq+fw4khVFxbZlLIg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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