SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dc674d9cabb32d2b93f7f54a5ffd0a4ebdf249bdbecc04bd5c2d1dfe8fea3dc' 
  AND token = 'v0wOtvS3PqEbn3VMQqAuVmME1m5pVyUq8B4U5V/Tf/0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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