SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44da12b6cf87d6c85f374b35137f9eea3b3571f2fd291c53d5dae79193be4f7b' 
  AND token = 'Dvg4e9atE4NKgOQaQlcMniXnc6HXKaVA6VPQwTSLO4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}