SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '537b7df57d7cdceb8b5eaff8b34fe18c0ceb80b02c112d0f1cd993708bcc5b24' 
  AND token = 'TsRiv2mnPCCbkuv7scqmTwwmGXkC/kGPYxpORF40GE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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