SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32c9dd9ab6dbd9531c2fd5b6f585ac1b8d88788485bfb6c221c46ae395ca8712' 
  AND token = 'iGn/qkYZqDJVjwZixcbRKc7+Mo6hKHDi3fWwYTw8S94=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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