SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da0a802fc4a598fd4d41fbd7b623f53ce7794268aa5dbd9abc1008114947c376' 
  AND token = 'iytj3PILm3PK88AlLWVECV+6WL7YBopPq7rh+7G8AwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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